Occupant propelled rotatable seesaw

ABSTRACT

A turning seesaw which has a fulcrum unit having an upper shaft, an eccentric shaft and a lower shaft on a support. A turning lateral rod is so secured to the upper shaft of the fulcrum as to allow elevational and horizontal turning. At least one upper connecting rod is engaged at one end with a portion of the turning lateral rod intermediate the fulcrum unit and its end, and engaged at the other end with the eccentric shaft of the fulcrum unit. Two pairs of handling rods are pivotally secured to both sides of the turning lateral rod so as to rotate along the axis of the turning lateral rod in a rocking fashion. Two lower connecting rods are each pivotally secured at one end to the lower end of the handling rod and pivotally secured at the other end to the lower shaft of the fulcrum unit, and two seats are mounted at both ends of the turning lateral rod.

United States Patent 1 Tada I [451 Sept. 11, 1973 OCCUPANT PROPELLEDROTATABLE SEESAW [75] lnventor: Minoru Tada,l(awaguchi-City,

Japan [73] Assignee: Kabushiki Kaisha Chuogoraku Kenkyusha, Tokyo, Japan[22] Filed: June9, 1971 [2]] Appl. No.: 151,272

Primary Examiner-Anton O. Oechsle Assistant Examiner-Arnold W. KramerAttorney-George B. Oujevolk [5 7] ABSTRACT A turning seesaw which has afulcrum unit having an upper shaft, an eccentric shaft and a lower shafton a support. A turning lateral rod is so secured to the upper shaft ofthe fulcrum as to allow elevational and horizontal turning. At least oneupper connecting rod is engaged at one end with a portion of the turninglateral rod intermediate the fulcrum unit and its end, and engaged atthe other end with the eccentric shaft of the fulcrum unit. Two pairs ofhandling rods are pivotally secured to both sides of the turning lateralrod so as to rotate along the axis of the turning lateral rod in arocking fashion. Two lower connecting rods are each pivotally secured atone end to the lower end of the handling rod and pivotally secured atthe other end to the lower shaft of the fulcrum unit, and two seats aremounted at both ends of the turning lateral rod.

1 Claim, 3 Drawing Figures PAIENTED FIG.3.

INVENTOR.

This invention relatesto a turning seesaw.

Heretofore, the conventional turning seesaw which could turn merelyturned horizontally and had a lateral rod around a fulcrum as a centerso that the motion was simple and uninteresting and yet its rotatingmotion was fast so as to be dangerous with the result that it was not agood plaything. for a child.

This invention contemplates to eliminating the aforementioneddisadvantages of the conventional turning seesaw and to provide a noveland improved turning seesaw which is variable and interesting.

It is an object of the present invention to provide a turning seesawwhich has'a turning lateral rod and this rod also moves elevationally upand down.

It is another object of the present invention to provide a turningseesaw which is not dangerous for children.

According to one aspect of the present invention, the foregoing andother objects are, in one aspect, attained by the provision of a turningseesaw having a fulcrum unit with an upper shaft, eccentric shaft and alower shaft on a support. A lateral rod is secured to the upper shaft ofthe fulcrum unit so as to allow turning in the horizontal plane as wellas up and down vertical movement. At least one upper connecting rod isengaged at one end with an intermediate portion of said turning lateralrod lying between the pivot point and the end of the rod and engaged atthe other end with the eccentric shaft of the fulcrum unit, two pairs ofhandling rods are pivotally secured at each end of the turning lateralrod on both sides thereof so as to rotate longitudinally along inarocking motion the axis of the turning lateral rod. Two lower connectingrods are each respectively pivotally secured at one end to the lower endof one of the handling rod and pivotally secured at the other end to thelower shaft of the fulcrum unit, and two seats are mounted at both endsof said turning lateral rod.

The invention, as well as other objects and advantages thereof will bebetter understood by reference to the following detailed descriptionwhen taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a front view of the turning seesaw constructed according tothe present invention;

FIG. 2 is a perspective view of the seesaw shown in FIG. 1; and

FIG. 3 is an explanatory view showing the principle of motion ofthisseesaw.

Reference is now made to the drawings, wherein like reference numeralsdesignate identical, or corresponding parts throughout the severalviews, which show one embodiment of the turning seesaw of thisinvention.

A fulcrum unit 2 having an upper shaft 2', eccentric shaft 2" and lowershaft 2" is mounted on a support 1, and the center portion of a turninglateral rod 3 having a center portion curved downwardly is so secured tothe upper shaft2' of the fulcrum unit 2 as to turn in the horizontalplane and also be able to rock up and down vertically. As shown anengaging cylinder 4 is pivotally engaged with the center of the turninglateral rod 3 and is placed on to the upper shaft 2' of the fulcrumshaft 2 so as to provide elevational and horizontal movement around theupper shaft 2'.

One or two upper connecting rods 5 are fastened at one end to anintermediate'position 3' of the turning lateral rod 3 between thefulcrum unit and the end of lateral rod 3, and are so engaged at theother end with the eccentric shaft 2" of the fulcrum unit 2 as to'allowelevational and horizontal movement. In the drawings, upper connectingrods 5 are shown on both sides, but it may be sufficient with only oneside.

Two handling rods 6 are pivotally secured to both ends or sides 3" and3" of the turninglateral rod 3 so as to rock and rotate longitudinallyalong the axis of the turning lateral rod 3, and two lower connectingrods 8 are pivotally secured at one end to the lower ends 6 and 6 of thehandling rods 6 at the points 9 and also are pivotally secured at theother end to the lower shaft 2" of the fulcrum unit 2 through a ring 10engaged with the lower shaft 2".

Reference numeral 11 illustrates seats mounted at both ends of theturning lateral rod 3, l2 handles mounted to the upper ends of thehandling rods 6 for the children to grip so as to operate the turningseesaw, and pedals 13 are mounted to the lower ends of the lower ends 6'of the handling rods 6 for children to place their feet.

In operation, if children sit on seats 11 and push and pull the handlingrods 6 by the handles 12 in the same direction, the force produced bythe children for changing the angles of the handling rods 6 is convertedto forces which pull up one side of turning lateral rod 3 and which pulldown the other side of the turning lateral rod 3 with the result thatthe converted forces move the turning lateral rod 3 up :and down byeccentric shaft 2" of the fulcrum unit 2 through the upper connectingrod or rods 5 and at the same time turns the turning lateral rod 3around the fulcrum shaft 2. Thus, the turning lateral'rod 3 turns inwavy motion.

As heretofore explained, the turning lateral rod 3 turns in a wavymotion, and accordingly even if children of different weights ride onseats 11 of the seesaw, the turning lateral rod 3 will turn smoothly bythe turning inertia. On the other hand, if the weight or load is droppedat one seat 11 as in the case one child falls down from the seat 11,other seat drops down as once and only one side force is applied to thehandling rod 6 with the result that sufficient force cannot be appliedto eccentric shaft 2" and the turning motion of the turning lateral rod3 is immediately stopped. As a result, the turning lateral rod 3 willnot turn a half turn to hit the fallen child.

Thus, the turning seesaw of this invention requires the child tocooperate, and if their timing is not matched, the turning seesaw isimmediately stopped with the result that it is very effective for thedevelopment of the childs capacity of cooperation.

What is claimed is:

1. An occupant-propelled rotatable seesaw comprising, in combination,

a. a stand (1), having a fulcrum unit (2) including an upper shaft (2'),a lower shaft (2"') with a ring (10) rotatable thereon, and an eccentricshaft (2") therebetween;

b. a curved lateral rod (3) pivotally mountedon a central hollowengaging cylinder (4) with said cylinder rotatably disposed over theupper shaft (2'), the lateral rod curving downwards with seats (ll) atthe ends thereof;

c. at least one upper connecting rod (5) having one end connected to anintermediate point (3) on the lateral rod intermediate the fulcrum unit(2) and a rods (8) each pivotally connected to the lower part of arespective handling rod and said ring (10), whereby said seesaw willturn only when one person occupies each seat and works the handles, butone seat will drop and the seesaw motion will stop if one person fallsoff the other seat.

1. An occupant-propelled rotatable seesaw comprising, in combination, a.a stand (1), having a fulcrum unit (2) including an upper shaft (2''), alower shaft (2'''''') with a ring (10) rotatable thereon, and aneccentric shaft (2'''') therebetween; b. a curved lateral rod (3)pivotally mounted on a central hollow engaging cylinder (4) with saidcylinder rotatably disposed over the upper shaft (2''), the lateral rodcurving downwards with seats (11) at the ends thereof; C. at least oneupper connecting rod (5) having one end connected to an intermediatepoint (3'') on the lateral rod intermediate the fulcrum unit (2) and aseat (11) and the other end rotatably connected to the eccentric shaft;and, d. a pair of handling rods each pivotally secured to the lateralrod between a respective seat and said intermediate point, handles (12)at the upper part of the handling rods, pedals (13) at the lower part ofthe handling rods and a pair of lower connecting rods (8) each pivotallyconnected to the lower part of a respective handling rod and said ring(10), whereby said seesaw will turn only when one person occupies eachseat and works the handles, but one seat will drop and the seesaw motionwill stop if one person falls off the other seat.